Ballcocks are well known devices used for controlling the water level in a tank such as the reservoir for a flush toilet. Ballcocks such as those disclosed in U.S. Pat. Nos. 2,808,850 and 2,911,000 issued to O. K. Doyle on Oct. 8, 1957, and Nov. 3, 1959, are known to make use of a float that moves in response to the level of water in the flush tank, while being guided telescopically by a guide mast.
U.S. Pat. No. 2,808,850 discloses use of a pilot controlled valve structure for a ballcock, positioned at the upper end of a water intake pipe located within a flush tank. The pilot controlled valve structure is housed in a two piece casing that includes a float-actuated lever pivotally mounted upon the upper, or cap, portion of the casing. The casing's cap is the uppermost casing part that connects, through a bayonet-type connection, to a lower, cup-shaped casing part. The control valve disclosed by the patent is located within the two-piece casing and includes a pair of nested, cup-shaped, flexible seal units, or valving members, with spaced horizontal, or transverse, wall portions that define and bound a pilot pressure chamber. The control valve also includes an elongated control pin, or pilot valve, that is operatively connected to the float actuated lever. The control pin is arranged to project through axially aligned openings in the spaced, transverse wall portions of the flexible seal units. The transverse wall portion of the lower nested seal unit serves as a diaphragm to control inflow of water to the flush tank in response to pressure changes in the pressure chamber.
The ballcock's valve in U.S. Pat. No. 2,808,850 is positioned at the top of the mast and is, accordingly, above the tank's water level part of the time. A submerged location adjacent the bottom of the flush tank is desirable for a ballcock valve, because the presence of water surrounding the valve at substantially all times aids to reduce the sound level of the incoming water.
U.S. Pat. No. 2,911,000 discloses another type of control valve that includes nested members. The lower member in said U.S. Pat. No. 2,911,000 is provided with an outer skirt to prevent water flow through air intake openings in the housing during the time the valve is open. When the valve is closed then the skirt falls away from the openings. Air then flows through the openings and thereby prevents siphoning.
The valve body may be formed of corrosion resistant plastic as disclosed in, for example, U.S. Pat. No. 3,194,258 issued to R. W. Grant on July 13, 1965.
U.S. Pat. No. 3,495,803 issued to A. Schoepe, et al. on Feb. 17, 1970, discloses a submerged ballcock valve for controlling the level of water in the flush tank of a toilet. The disclosed valve is of the pilot type having an axially movable pilot pin to control operation of the valve: A filtering and circuitous path noise reducing member is disclosed.
U.S. Pat. No. 3,576,199 issued to A. Schoepe, et al. on Apr. 27, 1971, discloses a ballcock valve having a submerged, reduced vertical height, unitary, molded lower housing member that provides an axial flow intake portion and an annular outlet flow portion. A removable fitting that provides filtering means is positioned in a filtering chamber defined in the path of the outlet flow in the lower housing member. The upper end of the lower housing member is adapted for the mounting of the upper housing member which carries a mast-like guide for a float.